With gradual development of Internet Protocol (IP) network technologies, an increasing number of services are transmitted by using an IP network, where the services include third generation mobile communications (3G) services, VIP private line services, wireless local area network (Wireless LAN, WLAN) services, Long Term Evolution (LTE) services, and the like. A networking structure of a typical bearer network in an IP network is shown in FIG. 1. Service data enters a network though a service access port 1, and a ring-shape networking structure is used in the network, including an access ring, an aggregation ring, and a core ring. Intra-ring lines are connected through intra-ring ports, rings are connected through inter-ring ports, and the service data is transmitted through the intra-ring lines of the rings and the inter-ring ports.
According to different services to which a service access port accesses, various types of ports may be used, such as an Ethernet port and an asynchronous transfer mode (ATM) port. In order to construct a network on a premise that the network is properly planned, a data flow rate on a new service access port that is to be added is generally simulated in a planning phase, and an impact on the bearer network after the new service access port is added is further analyzed. In the prior art, a data flow rate on a service access port is simulated by collecting information about a demand of using a network form a user, which leads to higher costs; and because a collected user sample not only has a random feature, but is also incapable of fully reflecting an actual network using situation of the user, accuracy of a simulated result is relatively low.